1. Technical Field
The present invention relates to a method for charging and discharging a smart battery of an electronic equipment and, more particularly to a method for controlling the charging and discharging of a smart battery of an electronic equipment even if information data from the smart battery is not correct.
2. Related Art
Generally, batteries are used to supply power to portable electronic equipments such as personal computers, radios, radiophones, stereo cassette tape players etc. Such batteries are typically available in two different types such as those characterized as rechargeable or non-rechargeable and exhibit different end of life voltage characteristics and effective resistance. Nonrechargeable battery types are those ordinary alkaline batteries that should not be subjected to recharging attempts. Rechargeable battery types are those nickel-cadmium (Ni--Cd), nickel-hydrogen (Ni--H) and nickel metal-hydride (Ni--MH) batteries that should be charged at different rates with different conditions by different types of charging techniques such as disclosed in U.S. Pat. No. 5,430,363 for Charging Device And Method Performing Battery Activation Function issued to Kim, U.S. Pat. No. 5,686,815 for Method And Apparatus For Controlling The Charging Of A Rechargeable Battery To Ensure That Full Charge Is Achieved Without Damaging The Battery issued to Reipur et al., U.S. Pat. No. 5,691,624 for Method And Apparatus For Detecting A Full-Charge Condition While Charging A Battery issued to Im et al., and U.S. Pat. No. 5,770,938 for Real-Time Charging Control Of A Fast Battery Charger issued to Kao.
Traditional rechargeable batteries pose a number of problems, however. First, the user has little advance knowledge that the battery is about to run out or how much operating time is left. Second, the electronic equipment powered by the battery cannot determine if the battery, in its present state, is able to supply adequate power for an additional load. Third, the battery chargers must be individually tailored for use with a specific battery chemistry and cell design and may cause damage if used on another battery with a different battery chemistry or cell design. In order to address these problems and to maximize the useful life of a rechargeable battery, a dedicated microprocessor has been incorporated into a battery for intelligent battery management. These are known as "smart" batteries, and are currently available with different configurations as disclosed, for example, in U.S. Pat. No. 5,432,429 for System For Charging/Monitoring Batteries For A Microprocessor Based System issued to Armstrong, II et al., U.S. Pat. No. 5,600,230 for Smart Battery Providing Programmable Remaining Capacity And Run-Time Alarms Based On Battery-Specific Characteristics issued to Dunstan, U.S. Pat. No. 5,606,242 for Smart Battery Algorithm For Reporting Battery Parameters To An External Device issued to Hull et al., U.S. Pat. No. 5,652,502, U.S. Pat. No. 5,691,621 and U.S. Pat. No. 5,710,501 for Battery Pack Having A Processor Controlled Battery Operating System issued to van Phuoc et al., and U.S. Pat. No. 5,747,189 for Smart Battery issued to Perkins. The operation of a smart battery is well known, and therefore need not described herein. However, I have observed that any time, the charge information from the smart battery is incorrect or false, the smart battery can be overcharged or not charged at all. Another problem of a smart battery is that, when discharged, the information of the battery such as the remaining capacity can be incorrectly provided.